Pressure sensors have become ubiquitous the past few years as they have found their way into many types of products. Utilized in automotive, industrial, consumer, and medical products, the demand for pressure sensors has skyrocketed and shows no signs of abating.
Pressure sensors may include pressure sensor chips as well as other components. Pressure sensor chips may include a diaphragm or membrane. Typically, this membrane is formed by creating electronic circuitry, such as a Wheatstone bridge in a silicon wafer, then etching away the silicon from the opposite surface forming a cavity until a thin layer of silicon is formed beneath the electronic circuitry. The thin layer is a membrane that may be surrounded by a thicker, non-etched silicon water portion forming a frame. When a pressure sensor chip in a pressure sensor experiences a pressure, the membrane may respond by changing shape. This change in shape causes one or more characteristics of electronic components on the membrane to change. These changing characteristics can be measured, and from these measurements, the pressure that the pressure sensor chip is exposed to can be determined.
Pressure sensors may be used to measure a pressure of a fluid, where the fluid may be a gas, such as air, or a liquid, such as water. The sensed pressure may be used directly, for example, in a tire pressure sensor. The sensed pressure may be used to determine values of related parameters, such as flowrate. Unfortunately, these systems may be complicated to design, and may be expensive and bulky in their implementation.
Thus, what is needed are pressure sensors, where the pressure sensors may be used in flowrate monitoring or measuring systems and may provide simple, low-cost designs that are readily implemented.